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authorGerd Hoffmann <kraxel@redhat.com>2021-12-08 08:01:46 +0100
committermergify[bot] <37929162+mergify[bot]@users.noreply.github.com>2021-12-13 14:47:37 +0000
commit41d8bb30386ceab55787fc9f5aac6434e2493e27 (patch)
tree0acfd698aa9285b09ceb4763f13ce883f9ca5b0f
parent759e3c6d2128f6b2673f95437854f067a532e59a (diff)
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OvmfPkg/PlatformPei: stop using cmos for memory detection
Not needed for qemu 1.7 (released in 2013) and newer. Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=3593 Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> Acked-by: Ard Biesheuvel <ardb@kernel.org>
-rw-r--r--OvmfPkg/PlatformPei/MemDetect.c59
1 files changed, 4 insertions, 55 deletions
diff --git a/OvmfPkg/PlatformPei/MemDetect.c b/OvmfPkg/PlatformPei/MemDetect.c
index 1bcb5a08bc..fb38e3c39d 100644
--- a/OvmfPkg/PlatformPei/MemDetect.c
+++ b/OvmfPkg/PlatformPei/MemDetect.c
@@ -38,7 +38,6 @@ Module Name:
#include <Library/QemuFwCfgSimpleParserLib.h>
#include "Platform.h"
-#include "Cmos.h"
UINT8 mPhysMemAddressWidth;
@@ -322,51 +321,11 @@ GetSystemMemorySizeBelow4gb (
{
EFI_STATUS Status;
UINT64 LowerMemorySize = 0;
- UINT8 Cmos0x34;
- UINT8 Cmos0x35;
Status = ScanOrAdd64BitE820Ram (FALSE, &LowerMemorySize, NULL);
- if ((Status == EFI_SUCCESS) && (LowerMemorySize > 0)) {
- return (UINT32)LowerMemorySize;
- }
-
- //
- // CMOS 0x34/0x35 specifies the system memory above 16 MB.
- // * CMOS(0x35) is the high byte
- // * CMOS(0x34) is the low byte
- // * The size is specified in 64kb chunks
- // * Since this is memory above 16MB, the 16MB must be added
- // into the calculation to get the total memory size.
- //
-
- Cmos0x34 = (UINT8)CmosRead8 (0x34);
- Cmos0x35 = (UINT8)CmosRead8 (0x35);
-
- return (UINT32)(((UINTN)((Cmos0x35 << 8) + Cmos0x34) << 16) + SIZE_16MB);
-}
-
-STATIC
-UINT64
-GetSystemMemorySizeAbove4gb (
- )
-{
- UINT32 Size;
- UINTN CmosIndex;
-
- //
- // CMOS 0x5b-0x5d specifies the system memory above 4GB MB.
- // * CMOS(0x5d) is the most significant size byte
- // * CMOS(0x5c) is the middle size byte
- // * CMOS(0x5b) is the least significant size byte
- // * The size is specified in 64kb chunks
- //
-
- Size = 0;
- for (CmosIndex = 0x5d; CmosIndex >= 0x5b; CmosIndex--) {
- Size = (UINT32)(Size << 8) + (UINT32)CmosRead8 (CmosIndex);
- }
-
- return LShiftU64 (Size, 16);
+ ASSERT_EFI_ERROR (Status);
+ ASSERT (LowerMemorySize > 0);
+ return (UINT32)LowerMemorySize;
}
/**
@@ -396,12 +355,9 @@ GetFirstNonAddress (
// If QEMU presents an E820 map, then get the highest exclusive >=4GB RAM
// address from it. This can express an address >= 4GB+1TB.
//
- // Otherwise, get the flat size of the memory above 4GB from the CMOS (which
- // can only express a size smaller than 1TB), and add it to 4GB.
- //
Status = ScanOrAdd64BitE820Ram (FALSE, NULL, &FirstNonAddress);
if (EFI_ERROR (Status)) {
- FirstNonAddress = BASE_4GB + GetSystemMemorySizeAbove4gb ();
+ FirstNonAddress = BASE_4GB;
}
//
@@ -773,7 +729,6 @@ QemuInitializeRam (
)
{
UINT64 LowerMemorySize;
- UINT64 UpperMemorySize;
MTRR_SETTINGS MtrrSettings;
EFI_STATUS Status;
@@ -832,12 +787,6 @@ QemuInitializeRam (
// memory size read from the CMOS.
//
Status = ScanOrAdd64BitE820Ram (TRUE, NULL, NULL);
- if (EFI_ERROR (Status)) {
- UpperMemorySize = GetSystemMemorySizeAbove4gb ();
- if (UpperMemorySize != 0) {
- AddMemoryBaseSizeHob (BASE_4GB, UpperMemorySize);
- }
- }
}
//